FIX: RDO Resultset.Update Using ODBC Cursors Does Not Time Out If Data Is Locked

If you're trying to update your rdoResultset on an rdoConnection with a CursorDriver of rdUseOdbc, the attempt to update the data in your database will not time out if that data is locked.

Microsoft has confirmed that this is a bug in the Microsoft products that are listed at the beginning of this article.

This bug was corrected in Visual Studio 6.0 Service Pack 3. For more information about Visual Studio service packs, please see the following articles in the Microsoft Knowledge Base:

194022 INFO: Visual Studio 6.0 Service Packs, What, Where, Why  (http://support.microsoft.com/kb/194022/EN-US/ )

194295 HOWTO: Tell That Visual Studio 6.0 Service Packs Are Installed  (http://support.microsoft.com/kb/194295/EN-US/ )

When you attempt to update data that is locked, most client-server databases, such as SQL Server and Oracle, keep trying to update that data until the length of time specified in the QueryTimeout value has expired. With RDO 2.0 prior to Visual Studio 6.0 Service Pack 3, the QueryTimeout information was not specified in the attempt to update and the attempt would never time out.

This problem only occurs when using an rdoConnection with a value of rdUseOdbc for the CursorDriver property. With all other values for the CursorDriver property, this behavior does not occur.

Steps to Reproduce Behavior

1. Create a new Visual Basic project.
2. Add a reference to RDO 2.0 in your project.
3. Add the following code to your project.

   Private Sub Form_Load()
       Dim cn1 As rdoConnection, cn2 As rdoConnection
       Dim rs1 As rdoResultset
       Dim strConn As String, strSQL As String
       
       strConn = "Driver={SQL Server};Server=MyServer;" & _
                 "Database=pubs;UID=MyUID;PWD=MyPWD;"
       strSQL = "SELECT * FROM Authors"
       
       Set cn1 = New rdoConnection
       cn1.CursorDriver = rdUseOdbc
       cn1.Connect = strConn
       cn1.EstablishConnection
           
       Set rs1 = cn1.OpenResultset(strSQL, rdOpenKeyset, rdConcurValues)
       
       Set cn2 = New rdoConnection
       cn2.CursorDriver = rdUseOdbc
       cn2.Connect = strConn
       cn2.EstablishConnection
       cn2.BeginTrans
       strSQL = "UPDATE Authors SET Au_FName = 'Test1' " & _
                "WHERE Au_ID = '" & rs1!Au_ID & "'"
       cn2.Execute strSQL
   
       rs1.Edit
       rs1!Au_FName = "Test2"
       rs1.Update
       
       cn2.RollbackTrans
       cn2.Close
       Set cn2 = Nothing
       
       rs1.Close
       Set rs1 = Nothing
       cn1.Close
       Set cn1 = Nothing
   End Sub
   					

   This code assumes that you are using RDO 2.0 to communicate with SQL Server 6.5 or 7.0. You need to modify the connection string to communicate with your database. If you're not using SQL Server, you might also need to modify the query strings.
   
   
4. Run the project.

If you're using the version of RDO 2.0 that ships with Visual Studio 6.0 Service Pack 3, you'll receive an error message stating that the timeout expired. If you're using an earlier version of RDO 2.0 (6.00.8169 or prior), the attempt to update your data will not time out.